“…It describes also the evolution of density and temperature of a self-attracting cluster of Brownian particles in a ball of R 3 in the limit of infinite thermal conductivity (see e.g. [1], [4] and [7]). Here, τ > 0 is time, x is the spatial variable, n stands for the density, ψ is the gravitational potential (defined by (1.2), (1.4)), E is the total energy, which is assumed to be constant, and θ is the (uniform) temperature.…”